1. Field of the Invention
The present invention relates to safety trailer hitches of the type normally used to tow trailers such as those carrying boats, utility trailers and camping trailers of various types.
2. Description of the Prior Art
The prior art apparatus normally found uses various safety chains between the trailing and towing vehicles to maintain the alignment of the trailing vehicle with the towing vehicle should the socket become disengaged from the ball. Commonly a substantial amount of slack is necessary in the chain so as to allow a normal swiveling action of the trailer. This slack may create problems and inherent risk should the hitch break or in some other way become disconnected, thereby leaving the chain as the only connection between the trailer and the vehicle. Ultimately, this results in a rhythmic swing from side to side that culminates in a whipping action causing loss of control of towing vehicle.
The prior art also purports to teach the use of a yoke which is mounted on a towing vehicle and is arranged to swing to a position overlying the coupling and ball (U.S. Pat. No. 3,759,548). Among other differences, this particular device has no anti-theft feature to it. Also, the design of the housing supporting the yoke in this particular patent would restrict the angle at which the socket can rotate vertically around the ball and thereby creates an unsafe situtation where the trailer tongue could bind against the yoke causing potentially large vertical forces to be applied to the tow bar and trailer tongue and possibly shear off the ball socket tightening knob. U.S. Pat. No. 4,032,171 apparently contains this identical flaw where the housing may bind against the trailer tongue in situations where the socket rotates vertically about the ball when the vehicle is turned sharply. In this particular patent, the tongue will bind against the housing creating a further unsafe situation when the towing vehicle is turned to a severe angle in relation to the trailer this binding occuring at substantially less than a ninety degree (90.degree.) angle. U.S. Pat. No. 3,605,457 appears to teach a device which can be installed on a trailer tongue ball socket which would prevent unauthorized persons from inserting their own balls into the ball socket and driving off with an unattended trailer. It cannot be used to tow a trailer and it requires a dummy tow ball.